Fork adjustment for industrial trucks



F. A. VOSSENBERG FORK ADJUSTMENT FOR INDUSTRIAL TRUCKS 2 Sheets-Sheet; 1

Filed April 14, 1947 INVENTOR JJ nfi/fg BY ATTORNEY INVENTQR 7 F14 Vossenery BY Mz-Zolm ATTORNEY 2 Sheets-Sheet 2 F A VQSSENBERG FORK ADJUSTMENT FOR INDUSTRIAL TRUCKS Filed April l4, 1947 Patented Oct. 4, 1949 FORK ADJUSTMENT FOR INDUSTRIAL TRUCKS Frank A. Vossenberg, Philadelphia, Pa., assignor to The Yale & Towne Manufacturing'Company, Stamford, Conn, a corporation of Connecticut Application April 14, 1947, Serial No. 741,163

'16 Claims. (01. 214-113) This invention relates to an industrial truck of the type in which an elevating platform or carriage is adapted for vertical movement, generally on primary and secondary uprights. In trucks of the particular class, it is frequently desirable that the carriage comprise lifting forks and that these forks be adapted for lateral adjustment for various types of loads. This is all well understood by those skilled in the art.

For adjusting the forks laterally, it is usual to use means that may take the form of a shaft having two series of screw threads in opposed directional relationship, and. to assemble the two screws to nuts or the equivalent thereof movable with the forks. Through this type of structure, a simple rotation of the shaft will effect the movement of the forks toward and aWayfrom one another, as will be readily appreciated and as is standard in the art.

In order for an operator to actuate the adjusting shaft or other fork adjusting means of the prior art, the operator must descend from his truck platform to obtain access to the adjusting means. If the truck is of the very high lift type, it may even be necessary for the operator to lower the carriage so that-the forks and the adjusting means may be accessible to him.

It is the object of. my invention to contribute an effective structure for operating the fork adjusting means, and with the said structure accessible to the operator of the truck in practically all the positions of the elevating carriage.

As a feature of my invention, I utilize a operating mechanism for-the fork adjusting means of the truck so mounted as to move with the carriage and yet having a portion thereof available for actuation by an operator standing on the truck platform. "As a more particular feature of the invention, the operating mechanism may comprise .an assembly pivoted to the carriage and movable by gravity downwardly so as to hang downwardly whenthe carriage is in a fully elevated position. -By providing means on which the assembly may rest as the carriage moves downwardly, a part of the assemblyis held against movement with the carriage after the carriage reaches a predetermined position, and thereby remains accessible through pivotal movement relatively to the carriage.

I have thus outlined the general nature of my invention and its relation to the prior art in order that the description thereof that follows may be better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which my disclosure is based, may readily be utilized as the basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims to be granted me shall'be of sufiicient breadth to prevent the appropriation of my invention by those skilled in the art.

Referring now to the drawings, Fig. 1 is an elevation of a truck in which my invention is embodied, showing the lifting forks and the operating assembly for the fork adjustment means in two positions. Fig. 2 is a view of the truck of Fig. 1, showing the elevating carriage and forks in an extreme upward position, and with the operating mechanism for the fork adjustment means in a third position. Fig. 3 is an enlarged view showing the operating assemblyfor the fork adjustment 'means in three positions. Fig. 4 is an end view of the parts of Fig. 3. Fig. 5 is a section taken along lines 5-5 of Fig. 4, while Fig. 6 is a section taken along lines 6-6 of Fig. 4.

Referring now more particularly to the drawings, I show my invention embodied in a truck designated generally by reference numeral [0. This truck is of the high lift type well known in the art and is equipped with primary uprights II and secondary uprights l2 movable on the primary uprights through suitable means. Mounted for movement on the secondary uprights is what is known generally as an elevating adapted to coact, it being understood that my invention may be used with other types of forks and fork adjusting means, as those skilled in the art will appreciate.

Each of the forks l4, i5 is formed with abore l6 as is probably best seen inFig. 6, through which passes a shaft ll. The left hand portion of shaft H, as seen in Fig. 6, carries threads l8 that are in engagement with a nut l9. The nut I9 is cylindrical in form, as can best be appreciated by glancing at Fig. 4, and'the threaded bore of the said nut is in alignment with the bore l6 of fork M. "The right hand end of the shaft I! is threaded as shown at 20 with the threads 20 running in a direction opposite that of the threads 18'. ThreadsZO are in engagement with the internal threads of a cylindrical nut 2| similar to the nut l9, and associated with the fork [5 in the same manner as the nut I9 is associated with the fork i4.

Shaft I! is mounted in bearing lugs 22, 23, and 24 formed integrally with the carriage i3, and for protecting the threads of the shaft against injury, a plate 25 is secured to the three bearing lugs 22, 23, 24 as is probabl best shown in Figs. 4 and 6. Through discs or washers 23 pinned at 21 to the shaft ll, the shaft is held against endwise movement relatively to the carriage l3. It will now be obvious that a simple rotation of the shaft IT in one or the other direotion will, through the threaded relationship of the shaft and the forks l4, l5, effect the movement of the forks toward and away from one another. Insofar as I have described the truck structure, it is old and well known in the art. My invention resides particularly in the means I have developed for rotating the shaft ii in all positions of the elevating carriage l3 illustrated in the several drawings, and preferably by means accessible to an operator standing on the platform 39 of the truck. It will be well to reiterate that my invention may be used with other fork adjustment means by those skilled in the art.

As is best seen in Fig. 6, the shaft IT has rotatably mounted thereon a circular bearing block 3| in thrust relation to the bearing lug 22. casing 32 forming the housing of the operating assembly of the fork adjusting means. The main side plate of the metal casing 32 is designated by reference numeral 33, and it is formed with a short sleeve portion 34, best seen in Fig. 6, whereby it is further supported for rotation on the shaft H. In thrust relation to the sleeve 34 is a sprocket 35 pinned at 36 to the shaft I1 and thereby holding in assembled relation on the shaft the sprocket 35 together with the metal casing 32. Through means of a removable plate 31, access may always be had to the sprocket 35 and the means holding it and the casing 32 assembled on the shaft [1.

The main side plate 33 of the metal casing 32 extends longitudinally for a considerable distance from the axis of shaft l1 and supports at its outer end a short shaft 38 to which is pinned or otherwise secured a sprocket 38. Secured also in some suitable way to the short shaft 38 is a hand wheel-4o, it being obvious that rotation of the hand wheel 43 will rotate the shaft 38 and the sprocket 39. A standard type of sprocket chain 4| is mounted about the two sprockets 35 and 39 so that rotation of sprocket 39 will effect the rotation of sprocket 35 and the consequent rotation of the shaft l'l. Naturally, this rotation of the shaft I? will move the forks l4, l5 toward and awa from one another as I have already indicated.

The metal casing 32 is freely rotatable about the shaft l1 and unless suitably controlled, will move by gravity into 'a downward position, to hang vertically in alignment with the shaft [7. The downward movement of the casing 32 is limited through means of' a limit lug 42 welded to the carriage [3 as best illustrated in Fig. 4. In Fig. 2 the metal casing 32 is shown in the position in which it is held by limit lug 42. Upward swinging movement of the casing 32 is also limited, and for the particular purpose there is welded to the main side plate 33 of the casing a pin 43 as best illustrated in Fig. 4. This pin, as is seen also inFig. 3,-prevents the clockwise Welded to this bearing block 3! is a metal to and formed with an outer flange 46.

4 movement of the casing 32 on the axis of shaft l1 beyond the position of Fig. 3.

To control and guide the movement of the casing 32 between its extreme positions illustrated in Fig. 2, and in solid lines in Fig. 3, I utilize a bracket 44 secured to one of the primary uprights ll of the truck, as best illustrated in Fig. 4. Bracket 44 supports at its extreme left end in Fig. 4 a sleeve 45 welded there- Obviously, the casing 32 will lie between the flange 46 and the end of bracket 44, resting on the sleeve 45, except when the casing is moved with the carriage to a position beyond the bracket '44 and sleeve 45 as seen in Fig. 2.

The construction of the means forming my invention will now be quite clear to those skilled in the art. briefly the operation thereof. Referring now to Fig. 3, the elevating carriage I3 is shown in its fully lowered position. At this time, the metal casing 32 will rest by gravity on the sleeve 45 while substantial clockwise rotation of the casing will be prevented through the limiting function of the pin 43. It is quite obvious that in this position of the parts, also illustrated in full lines in Fig. 1, the operator, while standing on the platform 30, may readily rotate the hand wheel 40 and through the sprockets 35, 39 and chain 4|, rotate the shaft 11 to adjust the forks I4, I5 to any desired position.

Let us say that the elevating platform is now raised to its intermediate position shown in dash and dotted lines above the full line position in Fig. 3. The casing 32 has now pivoted downwardly in a counterclockwise direction relatively to the carriage l3 and shaft l1, and lies in a substantially horizontal position. The wheel 40 is now in an extremely accessible position relatively to the operator on the platform 30. Of course, a simple rotation of the wheel will adjust the forks l4, l5.

Let us say that the elevating carriage is now moved to its upper position in Fig. 3, shown also in dash and dotted lines. The hand wheel 40 is now also in a very accessible position, but the casing 32 has swung counterclockwise downwardly into the most extreme position to which it can move, due to the action of the limit lug 42. The adjusting shaft I1 is, of course, readily operated through the operation of the hand Wheel 40. If the elevating carriage I3 is now raised to its extreme upper position indicated in Fig. 2, the metal casing 32 will move completely away from sleeve 45 supported by bracket 44. Of course, further counterclockwise rotation of the casing 32' relatively to the shaft I! will be prevented by the limit lug 42. Because of this relationship of the parts, the hand wheel is still accessible to an operator on the platform 30. Naturally, when the elevating carriage is lowered, the casing will. gradually move downwardly until it impinges against the sleeve 45, and thereafter the sleeve 45 will control its positioning, as has already been indicated.

I believe that with this explanation of the operation of my invention, the full, nature of my contribution to the art will be appreciated.

I now claim:

1. In an industrial truck, a pair of uprights, a carriage mounted for vertical movement on said uprights, a pair of forks. on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another,

actuating means for moving said forks laterally However, it will be well to outline I on said carriage, an operating assembly for said actuating means pivoted relatively to said carriage and including means to operate said actuating means in all pivoted positions of said operating assembly, and means on said uprights upon which saidoperating assembly rests as said carriage moves vertically on saiduprights.

2. In an industrial truck, a frame, a carriage mounted for vertical movement on said frame, a pair of forks mounted on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, actuating means for moving said forks laterally on said carriage, an operating assembly for said actuating means pivoted relatively to said carriage and including means to operate saidactuating means in all pivoted positions of said. operating assembly, and means on said frame upon which said operating assembly rests as'said carriage moves vertically on said frame.

3. In an industrial truck, a pair of uprights, a carriage mounted for vertical movement on said uprights, a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, actuating means for moving said forks laterally on said carriage, an operating assembly for said actuating means pivoted relatively to said carriage and including means to operate said actuating means in all pivoted positions of said operating assembly said operating assembly moving by gravity to a position angularly downward from said carriage toward said uprights when said carriage is elevated on said uprights, and a support on said uprights on which said assembly rests while one end thereof moves with said carriage whereby to hold said assembly in a position angularly upward from said carriage when said carriage is fully lowered on said uprights.

4. In an industrial truck, a pair of uprights, a carriage mounted for vertical movement on said uprights, a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one an,- other, actuating means for moving said forks laterally on said carriage, an operating assembly for said actuating means pivoted relatively to said carriage and including means to operate said actuating means in all pivoted positions of said operating assembly, said operating assembly moving by gravity to a position angularly downward from said carriage toward said uprights when allowed to pivot freely, a support on said uprights on which said assembly rests to control its pivotal movement and to hold said assembly in a position angularly upward from said carriage when said carriage is fully lowered, said assembly continuing to rest on said support until said carriage moves to a full upward position to carry said assembly beyond said support, and limit means on said carriage limiting the downward swinging movement of said operating assembly when said operatin assembly moves upwardly with said carriage beyond said support.

5. In an industrial truck, a main frame, a carriage mounted for vertical movement on said main frame, a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, actuating means for moving said forks laterally on said carriage, an operating assembly for said actuating means pivoted relatively to said carriage and including means to operate said actuating means in all pivoted positions of said operating assembly, said operating assembly extending linearly from its pivota substantial dis tancelso that when said carriage is fully lowered the outer end of the operating assemblywill be readily accessible at a point substantially above said carriage, and means on said main frame holding the outer end of the operating assembly against pivotal movement downwardly as said carriage moves downwardly on said main frame.

6. In an industrial truck, a main frame, a carriage mounted for vertical movement on said main frame, a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, actuating means for moving said forks laterally on said carriage, an operating assembly for said actuating means pivoted relatively to said carriage and including means to operate said actuating means in all pivoted positions of said operating assembly, said operating assembly extendin linearly from its pivot a substantial distance so that when said carriage is fully lowered the outer end of the operating assembly will be readily accessible at a point substantially above said carriage, means on said main frame holding the outer end of the operating assembly against pivotal movement downwardly as said carriage moves downwardly on said main frame, and manual means substantially at the outer end of the operating assembly for operating said operating assembly to actuate said fork actuating means.

7. In an industrial truck, a main frame, a carriage mounted for vertical movement on said main frame, a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, a shaft rotatable on said carriage and in operative relation to said forks to adjust said forks laterally when said shaft is rotated, an operating assembly freely pivoted relatively to said carriage on the axis of said shaft, means in said assembly for rotating said shaft in all pivoted positions of said assembly on the axis of said shaft, and means on said main frame upon which said operating assembly rests as said carriage moves vertically on said main frame.

8. In an industrial truck, a pair of uprights, a carriage mounted for vertical movement on said uprights, 'a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, a shaft rotatable on said carriage and in operative relation to said forks to adjust said forks laterally when said shaft is rotated, an operating as sembly pivoted relatively to said carriage on the axis of said shaft, means in said assembly for rotating said shaft in all pivoted positions of said assembly on the axis of said shaft, said operating assemblymoving by gravity to position angularly downward from said carriage toward said uprights, and a support on said uprights on which said assembly rests whereby to hold said assembly in a position angularly upward from said carriage when said carriage isfully lowered, and with said assembly continuing to rest on said support until said carriage moves to a full upward position beyond said support.

9. In an industrial truck, a pair of uprights, a carriage mounted for vertical movement on said uprights, a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, a shaft rotatable on said carriage and in operative relation to said forks to adjust said forks laterally when said shaft is rotated, a longitudinally extending mounting member pivoted relatively to said o r.

riage on the axis of said shaft, operating means movable on said mounting member for rotating said shaft in all pivoted positions of said casing on the axis of said shaft, and actuating means at the end of said longitudinally extending mounting member for actuating said operating means to rotate said shaft.

10. In an industrial truck, a pair of uprights, a carriage mounted for vertical movement on said uprights, a pair of forks on said carriage adapted f or adjustment laterally relatively to said carriage toward and away from one another, moving means in operative position between said forks to ad-' just said forks laterally, a longitudinally extending carrying member pivoted on said carriage, and means on the end of said longitudinally extending carrying member for controlling the actuation of said moving means in. all pivoted positions of said mounting member relatively to said carriage.

11. In an industrial truck, a pair of uprights, a carriage mounted for vertical movement on said uprights, a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, moving means on said carriage in operative relation to said forks to adjust said forks laterally when said means are moved, a carrying member pivoted on said carriage, means on said carrying member for controlling the actuation of said moving means in all pivoted positions of said carrying member relatively to said carriage, said mounting member moving by gravity on its pivot to a position angularly downward from said carriage toward said uprights, and a support on said uprights on which said mounting member rests whereby to hold said mounting member in a position angularly upward from said carriage when said carriage is fully lowered, and with said mounting member continuing to rest on said support, as said carriage moves upwardly on said uprights.

12. In an industrial truck, a pair of uprights, a carriage mounted for vertical movement on said uprights, a pair of forls on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, a shaft rotatable on said carriage and in operative relation to said forks to adjust said forks laterally when said shaft is rotated, a mounting member pivoted relatively to said carriage on the axis of said shaft, said mounting member extending linearly from its pivot a substantial distance, a sprocket on the shaft, a second sprocket mounted substantially at the outer end of the mounting member, a chain extending over said sprockets, and manual means for rotating said second sprocket and therefore said shaft.

13. In an industrial truck, a pair ofuprights, a carriage mounted for vertical movement on said uprights, a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, a shaft rotatable on said carriage and in operative relation to said forks to adjust said forks laterally when said shaft is rotated, a mounting member pivoted relatively to said carriage on the axis of said shaft,

said mounting member extending linearly from its pivot a substantial distance, a sprocket on the shaft, a second sprocket mounted substantially at the outer end of the mounting member, a chain extending over said sprockets, manual means for rotating said second sprocket and therefore said shaft, said mounting member moving by gravity to position angularly downward from said carriage toward said uprights, and a support on said uprights on which said mounting member rests whereby to hold said mounting member in a position angularly upward from said carriage when said carriage is fully lowered, and with said mounting member continuing to rest on said support as said carriage moves upwardly on said uprights.

14. In an industrial truck, a pair of uprights, a carriage mounted for vertical movement on said uprights, a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, actuating means for moving said forks laterally on said carriage, an operating assembly for said actuating means pivoted relatively to said carriage, and

1 means in said assembly for operating said actuating means in all pivoted positions of said operating assembly.

15. In an industrial truck, a frame, a carriage mounted for vertical movement on said frame, a pair of forks mounted on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, actuating means for moving said forks laterally on said carriage, an operating assembly for said actuating means pivoted relatively to said carriage, and means in said assembly for operating said actuating means in all pivoted positions of said operating assembly.

16. In an industrial truck, a main frame, a carriage mounted for vertical movement on said main frame, a pair of forks on said carriage adapted for adjustment laterally relatively to said carriage toward and away from one another, a shaft rotatable on said carriage and inopeartive relation to said forks to adjust said forks laterally when said shaft is rotated, an operating assembly freely pivoted relatively to said carriage on the axis of said shaft, and means in said assembly for rotating said shaft in all pivoted positions of said assembly on the axis of said shaft.

FRANK A. VOSSENBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,518,560 Carroll Dec. 9, 1924 1,556,262 Streeter Oct. 6, 1925 1,813,596 Abbe July '7, 1931 2,099,998 Berg Nov. 23, 1937 2,339,120 Ulinski Jan. 11, 1944 2,418,693 Breslav Apr. 8, 1947 2,420,828 King May 20, 1947 

